Nearly a fifth of the nation's full-power television stations will no longer reach at least 2 percent of viewers now covered by their existing analog signals after they switch to digital broadcasts in February, federal regulators say.
The Federal Communications Commission report comes amid mounting concerns that some consumers who rely on analog-only television sets could lose some or all over-the-air broadcast channels following the Feb. 17 digital transition even if they have purchased and hooked up digital converter boxes.
That's because many television stations will shift their broadcast footprints with the mandatory transition by changing transmitter locations, antenna patterns or power levels. The FCC is not requiring television stations to replicate their analog coverage.
Some viewers could also lose signals because of what's known as the digital "cliff effect."
Unlike analog signals, digital broadcasts either come in clear or not at all, meaning that those on the fringes of analog coverage areas will lose that reception entirely after the transition. Currently, they can still get fuzzy analog signals.
Some viewers may therefore need more powerful antennas — in addition to converter boxes — to continue receiving certain channels.
In a report released late Tuesday, the FCC said 319 of the nation's 1,749 full-power television stations, or 18 percent, will have a digital signal that reaches at least 2 percent fewer viewers than their current analog broadcasts.
Those numbers do not reflect viewers who will continue to receive channels after the transition because they subscribe to cable or satellite service — roughly 85 percent of viewers overall — or rely on so-called "translators" or repeaters to get reception.
What's more, many stations will be gaining viewers elsewhere even as they lose some of their existing viewers. About half of those 319 stations will reach more people overall after the transition.
Other stations will also reach fewer existing viewers, but below the 2 percent threshold. All told, 196 stations, or 11 percent of the 1,749 full-power TV stations, will reach viewers overall, while the rest will see gains.
Broadcasters can take a number of steps to restore service for those who may lose signals. Options include using translators or "fill-in" stations that operate on a different channel, using another station's digital spectrum to retransmit a signal, maximizing the station's power, changing the station's channel or changing its antenna pattern.
The National Association of Broadcasters had no comment on the FCC report.
The transition from analog to digital broadcasting is expected to free up valuable spectrum that can be used to deliver high-speed Internet access and other commercial wireless services and to connect police officers, fire fighters and other emergency workers.
Earlier this month, Congress passed a law requiring analog broadcasts of public safety announcements and information about the digital transition for 30 days following the transition.
The information to be broadcast will include details on how consumers can convert their television sets to receive digital signals.